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There are a lot of threads here discussing the move to DSP based room correction as well as all digital audio systems in high end HT's. Nyal hosted a great thread on a DIY software based system running J River. I am taking a different hardware approach and will document the project here over the next couple of months.

My former audo system was largely analog based on a Lexicon MC8. And of course a good portion of that audio chain was unbalanced. It was also rather complicated with a modified Lexicon MC8 for direct 8 channel analog in for BluRay. The crossover evolved from a tube based Marchand clone to a Berhinger DCX2496 with a DCX214 bass manager - but of course all I/O was analog.

Here are the new system specs:

1) All audio shall be digital up to the final DACs and onto the analog volume controller. I am using pro balanced 110ohm AES interconnects for the discrete audio and 75ohm for the SPDIF AC3 formats.

2) All analog audio shall be balanced at +4dbm - same as pro systems.

3) 16 speaker channels will be provided for. Note that this includes biampping, eg, the LCRs take up 6 channels alone.

4) DACs will be Lucid 88192 units (x2). I got four of these lightly used in an auction deal.

7) The DSP unit is based on the MiniDSP product and final analog preamp / volume controller will be DIY. This is my DIY Trinnov! I have dubbed the main DSP unit the "MC16". It generates 16 channels and since Lexicon never went beyond the MC12, I took the MC16 name for myself!

8) Calibration will be done with REW, which the DSP boards do have an interface.

As I will have access to the native DSP chips, I can build filters in firmware specific to my room if needed, a level of flexibility far beyond many off the shelf systems.

SUBS (2): Refurbished Phase Linear 700. This 1979 relic has been rebuilt and made more reliable with some current technology.

Surrounds: 5 channel DIY amp based on LM3886 chips, 75w per channel, Sl,Sr,Bl,Br,Bc. These amps are not the highest "audiophile" quality but more than sufficient for surround duty. I plan to add two height channels and will probably just build more of these amps.

To start I stripped all my direct analog input mods from the MC8 and added a simple 4 channel (equivalent 8 analog channels) AES transmitter board.
The MC8 is therefore stock in it's operation except that he MC8 volume control does not affect the digital outputs. I also discovered some of the Lexicon effects do tweak the individual channel gains. I will have to match that in my gain controller if needed, nothing is ever simple. Basically the MC8 in my HT has been demoted to an AC3/DTS and enhanced 7.1 digital only effects processor for those sources - DVD, Satellite, Media Server. I may still use the analog Zone 2 section for the other house TVs since it has a good 5.1/7.1 mixdown function.

The "VOL16" Unit:
The MiniDSP boards do not provide a good volume control solution. In addition I need a facility to tweak the individual speaker gains for room conditions. The Lexicon MC8 provides for this as do most processors but it's usually done in the analog section. As I am taking direct digital out, I lose this very important feature.I also am in the camp that believes gain control in an audio system is still best done analog. I do respect the opposing views as they have equally good science to back up their claims for digital volume control. As with anything, there are good analog and bad analog gain solutions as well as good and bad digital solutions. I hope to have designed a top notch analog solution here.

So here is the VOL16. This is a 16 channel computer controlled gain controller. It is based on Burr Brown PGA2310 VCA chips coupled with Analog Devices SSM 2141 and SSM2142 audio balanced line driver & receiver chips. These are all very good quality analog chips designed specifically for high end audio. The audio path is simple and clean. All power supplies including the +5v digital power for the CPU are linear, not switch mode. I was a little concerned about the VFD display high voltage inverter causing RFI but I can't see it on the audio signal at all - at least to -106db. Of course being CPU controlled, I have the ability for different presets as well as a plethora of other features which can be added. There is an RS232 port for external control running at 38K baud for fast response.

Main VCA board completed. The 16 relays are for physical mute of the outputs and have a user adjusatble turn on delay time via the front panel menu.

Chassis under construction I found some great rack mount PC chassis for the VOL16 and MC16. I put in a blue custom mounted 20x2 VFD display where the CDROM is intended to go. Silver face seems to be the new fashion over black so I opted for that.

Completed VOL16 under test and software development in my garage lab.

Rear panel. The lone RCA jack is a hardware mute switch closure that can be enabled and disabled on the fly via RS232 as well as an RS232 mute command. Both the external hardware and RS232 mute option action is soft - a very fast fade down so as not to produce clicks. The physical mute relays are only used for power up delay.

Let me try to interpret for Noah: RC equals Room Correction. Also, Trinnov's remapping can build sonic images where there are no speakers. It is not the same as re-routing to different speakers.

Jeff

Well the MiniDSP products do interface to REW so there is the room correction. I have used REW previously with the two Behringer DSP units I am taking out but it lacked the tight interface MiniDSP promises to provide.

But I still realize I am not duplicating a Trinnov exactly, perhaps not even close. But given the DSP horsepower I will have (4 Sharcs) as well as programming access to the DSP cores, the future is wide open for me to experiment with creating sound fields.

The main benefit here initially is I will be all digital up to the volume control and power amps. And I am not having to deal with HDMI issues in doing this. There will be an A-D/D-A step if I want to go through my legacy DBX processor which I use for older recordings and Laser disks but that can be switched out on the digital side.

Interesting project. Why didn't you just use a HTPC with a multichannel USB DAC ? I ask because this is my plan, looking at the 8ch exasound DAC, it's built around the ESS chip so volume control is built-in (for better or worst is open to debate).

Interesting project. Why didn't you just use a HTPC with a multichannel USB DAC ? I ask because this is my plan, looking at the 8ch exasound DAC, it's built around the ESS chip so volume control is built-in (for better or worst is open to debate).

Well I seriously looked at the JRiver approach and there is a great thread on this forum outlining exactly how to do it. The only issue is lack of external digital 7.1 input. This should not be difficult for them to add since the popular Lynx AES16 card which is used a lot with Jriver has 8 inputs and outputs. JRiver also doesn't decode all the advanced BluRay codecs due to licensing issues. And my media server which holds my legacy DVHS library is carefully set up to play out 1080i with an older version of VLC. I have tried newer VLC versions as well as other players and none look as good as my 1080i output via an SDI equipped NVidia card.

All in all if you don't have an extensive library of non BluRay HD the JRiver would be the best approach. It is much cleaner build wise as well as infinitely more upgradeable.

Well the MiniDSP products do interface to REW so there is the room correction. I have used REW previously with the two Behringer DSP units I am taking out but it lacked the tight interface MiniDSP promises to provide.

But I still realize I am not duplicating a Trinnov exactly, perhaps not even close. But given the DSP horsepower I will have (4 Sharcs) as well as programming access to the DSP cores, the future is wide open for me to experiment with creating sound fields.

The main benefit here initially is I will be all digital up to the volume control and power amps. And I am not having to deal with HDMI issues in doing this. There will be an A-D/D-A step if I want to go through my legacy DBX processor which I use for older recordings and Laser disks but that can be switched out on the digital side.

"But I still realize I am not duplicating a Trinnov exactly, perhaps not even close... "

To be clear, this "All Digital HT Rebuild" is not in any way replicating a "DYI -Trinnov." Credit is due to Glimmie, as Glimmie's project, while very very basic, is perhaps intended to experiment in the two areas Trinnov is know for: modifying both the individual loudspeakers performance and the soundfield as a whole. We have what appears to be some basic correction (mini-dsp has a few IIR filters per channel) along with a hand trimmed inter-channel mixing matrix. All done through manual tweeking and listening. Trinnov's work is done with advanced, 3D mathematical modeling and measurement systems.

None of the actual science Trinnov is known for is in evidence in Glimme's DYI experiment.

For those interested in Trinnov's research and development in this area:

"But I still realize I am not duplicating a Trinnov exactly, perhaps not even close... "

To be clear, this "All Digital HT Rebuild" is not in any way replicating a "DYI -Trinnov." Credit is due to Glimmie, as Glimmie's project, while very very basic, is perhaps intended to experiment in the two areas Trinnov is know for: modifying both the individual loudspeakers performance and the soundfield as a whole. We have what appears to be some basic correction (mini-dsp has a few IIR filters per channel) along with a hand trimmed inter-channel mixing matrix. All done through manual tweeking and listening. Trinnov's work is done with advanced, 3D mathematical modeling and measurement systems.

None of the actual science Trinnov is known for is in evidence in Glimme's DYI experiment.

For those interested in Trinnov's research and development in this area:

"But I still realize I am not duplicating a Trinnov exactly, perhaps not even close... "

I think I already stated my approach here is not exactly a Trinnov - not even close to quote. However your account of my work here is also less than accurate and a bit condesending.

First this is hardly "very very basic" nor is it some "experiment".There is nothing basic about this project. The MiniDSP does have tight integration with REW and therefore can do automated room EQ. Is it perfect? No, and neither is the Trinnov although I'm sure the Trinnov is a bit better. Nothing beats a manual human tweak as you should know. And since I have obviously mastered impedance controlled PC board layout software, FPGA development, Embedded processor development, and sophisticated test equipment, I think I can handle a manual REW setup.

In reading between the lines you seem to be sneering at this as some weekend amateur electronics project. Look at the lab picture. I see a $30K Tektronix 2ghz 4 channel scope. I also see 32 channel 1ghz logic analyzer. What is off camera is a full SMT/BGA rework station as well as a full prototype PC board lab. Yes I can and do make SMT boards at home. I can't do multilayer of course. This is hardly a casual hobbyist setup. I make one-off custom broadcast products on contract. In 1999 I made over 20 HDTV 4x2x2 HDSDI (that's 1.5gbs) protection switchers for DirecTV since no established manufacture could supply what they wanted. You know, the huge broadcast center up in Marina Del Rey on Culver Blvd.

This forum is getting to be more like the "How much did you spend" forum versus the Ultra high end. Ok, so I don't invest $30K in a Trinnov and ADA like some do here. But I have equivalent investment in high end electronic test and development equipment. The difference is I make money using that gear as well as enjoy the tax deductions. You get neither from buying high end HT gear! I tweak my system using proven engineering and scientific principles. I don't waste time with garden hose size power cords or interconnect cables that seem like they are sold at Tiffinay's. I wanted more resolution and detail. So I focused on eliminating redundant AtoD and DtoA conversions, not buying some silly $1500 SPDIF cable.

"But I still realize I am not duplicating a Trinnov exactly, perhaps not even close... "

I think I already stated my approach here is not exactly a Trinnov - not even close to quote. However your account of my work here is also less than accurate and a bit condesending.

First this is hardly "very very basic" nor is it some "experiment".There is nothing basic about this project. The MiniDSP does have tight integration with REW and therefore can do automated room EQ. Is it perfect? No, and neither is the Trinnov although I'm sure the Trinnov is a bit better. Nothing beats a manual human tweak as you should know. And since I have obviously mastered impedance controlled PC board layout software, FPGA development, Embedded processor development, and sophisticated test equipment, I think I can handle a manual REW setup.

In reading between the lines you seem to be sneering at this as some weekend amateur electronics project. Look at the lab picture. I see a $30K Tektronix 2ghz 4 channel scope. I also see 32 channel 1ghz logic analyzer. What is off camera is a full SMT/BGA rework station as well as a full prototype PC board lab. Yes I can and do make SMT boards at home. I can't do multilayer of course. This is hardly a casual hobbyist setup. I make one-off custom broadcast products on contract. In 1999 I made over 20 HDTV 4x2x2 HDSDI (that's 1.5gbs) protection switchers for DirecTV since no established manufacture could supply what they wanted. You know, the huge broadcast center up in Marina Del Rey on Culver Blvd.

This forum is getting to be more like the "How much did you spend" forum versus the Ultra high end. Ok, so I don't invest $30K in a Trinnov and ADA like some do here. But I have equivalent investment in high end electronic test and development equipment. The difference is I make money using that gear as well as enjoy the tax deductions. You get neither from buying high end HT gear! I tweak my system using proven engineering and scientific principles. I don't waste time with garden hose size power cords or interconnect cables that seem like they are sold at Tiffinay's. I wanted more resolution and detail. So I focused on eliminating redundant AtoD and DtoA conversions, not buying some silly $1500 SPDIF cable.

Glimmie:

To respond to your post- I believe your efforts are quite ambitious. If you in any way believe there is an attempt to reduce your efforts, quite the contrary. You exhibit excellent engineering skills and the motivation to have a great result. As well, your photos illustrate excellent workmanship.

As you chose to compare your efforts to a "DYI Trinnov," my effort is solely to distinguish the difference for those who are learning about Trinnov. It is very possible you may obtain excellent results, but this speaks to your personal abilities with the various elements you have pulled together. None the less, your project has very little in common with Trinnov, and I feel this should be clearly pointed out.

I would like to apologize for not being clearer regarding my comment "very very basic." I specifically am addressing the area where Trinnov brings unique value to the user- advanced algorithms based on many years of research and development- that aren't easily replicated. In that regard, given your proximity and interest, I would welcome the opportunity for you to experience a Trinnov system. It may give you "food for thought" as you move forward in your project.

You get neither from buying high end HT gear! I tweak my system using proven engineering and scientific principles. I don't waste time with garden hose size power cords or interconnect cables that seem like they are sold at Tiffinay's. I wanted more resolution and detail. So I focused on eliminating redundant AtoD and DtoA conversions, not buying some silly $1500 SPDIF cable.

By implication, you are saying that engineers at companies like shunyata that spend years developing said garden hose size power cords are charletans, and people using them and reporting dramatic improvements in sound quality are either snobs, hapless victims of placebo effect or both. Mildly presumptuous if you ask me.

Nothing wrong with eliminating a/d and d/a conversions of course - I've been doing that myself using commercially available high end gear and have only one a/d conversion in the chain (as do folks running hdmi into their SSP I might add).

By implication, you are saying that engineers at companies like shunyata that spend years developing said garden hose size power cords are charletans, and people using them and reporting dramatic improvements in sound quality are either snobs, hapless victims of placebo effect or both. Mildly presumptuous if you ask me..

Having grown alittle older and mellowed out alittle I've no longer feel compelled to argue with this practice or dismiss the people that do enjoy such product. But I will say this, audio cables are orders of magnitude more expensive than the cables we use in the lab to transmit 28Gbps signals with BER of 10^-17, we measure the cables with test gear that costs over $250k to be able to de-embed them from measurements.

P.S. are these high end audio cable companies large enough to actually have more than 1 designer/engineer ? I thought most of these small companies would be the work of a single man.

Having grown alittle older and mellowed out alittle I've no longer feel compelled to argue with this practice or dismiss the people that do enjoy such product. But I will say this, audio cables are orders of magnitude more expensive than the cables we use in the lab to transmit 28Gbps signals with BER of 10^-17, we measure the cables with test gear that costs over $250k to be able to de-embed them from measurements.

P.S. are these high end audio cable companies large enough to actually have more than 1 designer/engineer ? I thought most of these small companies would be the work of a single man.

Mostly they probably have one lead designer. I don't care one way or the other. They either work or they don't. And yes, they probably cost less than 10% of retail to manufacture. Don't care about that either. If you buy them at the right price you can get all your money out on resale.

By implication, you are saying that engineers at companies like shunyata that spend years developing said garden hose size power cords are charletans, and people using them and reporting dramatic improvements in sound quality are either snobs, hapless victims of placebo effect or both. Mildly presumptuous if you ask me.

Nothing wrong with eliminating a/d and d/a conversions of course - I've been doing that myself using commercially available high end gear and have only one a/d conversion in the chain (as do folks running hdmi into their SSP I might add).

Yes, that's precisely what I am saying.

And btw, there are no engineers working at Shunyata. At least not by the standards of electrical engineering I come from. Their claims including that test jig they demonstrate is nothing but junk science.

And btw, there are no engineers working at Shunyata. At least not by the standards of electrical engineering I come from. Their claims including that test jig they demonstrate is nothing but junk science.

Priceless. I think you should start a certification business. Designers would submit their resume, you would administer an exam, and those that pass could put the coveted "Glimmie certified" sticker on their products. What an idea to separate the legitimate designers from the charlatans and snake-oil salesmen!

Priceless. I think you should start a certification business. Designers would submit their resume, you would administer an exam, and those that pass could put the coveted "Glimmie certified" sticker on their products. What an idea to separate the legitimate designers from the charlatans and snake-oil salesmen!

Great idea! But sadly for me it's already been done many years ago. It's called the IEEE (yes I am a member). And then there's these places called universities that give out these things called degrees, Most legitimate employers in the electronics design and engineering industry expect to see one or at least equivalent demonstrable accomplishments and experience.

Then there's the PE (Professional Engineer) license. Any engineer practicing design services for hire where public safety is involved such as engineering the electrical system of a building must be a PE which is a state engineering exam on the level of difficulty as the BAR or MD license exams. There are PE's for electrical, mechanical, chemical, civil, structural and a few more. No I am not a PE because nobody ever got injured watching TV or movies so broadcast engineering is exempt, but used to still be licensed by the FCC and engineers were required to be licensed, Thank you Ronald Regan for deregulating and throwing out that measure of competence.

I am a bit surprised at you Edorr. Anyone who can afford six Shunyata power cords obviously has plenty of hobby income and must be doing something very well to earn that money. But the fact that you discount engineering professionals here like myself and others in favor of what you read in "Stereophile" or similar heavily advertiser supported magazines shows ignorance.

Do you argue with your MD when he discounts some article you read in "Better Homes and Gardens" about the benefits of herbal remedies?

Again where is the key personnel bio page on the Shunyata site so we may verify the credentials of their "engineers"? At least they are smart enough to keep that quiet. Other snake oil vendors like Audioquest are dumb enough to list credentials. Like extraordinary cable designer Bill Low, president of Audioquest. He has no engineering training or background whatsoever. Yet he routinely makes scientific discoveries about electrical transmission all the major accredited institutions all miss?

I am a bit surprised at you Edorr. Anyone who can afford six Shunyata power cords obviously has plenty hobby income and must be doing something very well to earn that money. But the fact that you discount engineering professionals here like myself and others in favor of what you read in Stereophile or similar magazines shows ignorance.

I try stuff at home and if I like what I hear I keep it, and if I don't I sell it. I have resold highly regarded and reviewed pieces of gear within 24 hours because I did not like them. I owned and resold $12K worth of Shunyata signal cables, because they did not work in my system - the Shunyata fanboys were telling me I made a big mistake and needed more burn in time, whatever.

Shnuyata powercables are second to none and work miracles in my system - many others have reported similar results. My be their chief designer is a charlatan and we're all idiots. May be the recording studios using their cabling are idiots as well. Who knows .... my money is on the empiricists.

Quote:

Originally Posted by Glimmie

Do you argue with your MD when he discounts some article you read in "Better Homes and Gardens" about the benefits of herbal remedies?

My wife was told numerous time by certified professionals in the medical (MD) field the swelling in her neck was nothing to be worried about and kept sending her back. I said they are full of **** and insisted she get a biopsy. Turns out to be thyroid cancer. Oh well.... My grandmother and brother in law both died of non diagnosed cancer. Kept sending her to the gym - turns out to be colon cnacer. The day I blindly accept the opinion of a certified MD as truth is the day I'll sell my Shunyata cables (at a profit of course).

Shnuyata powercables are second to none and work miracles in my system - many others have reported similar results.

Well I have asked you this before and you can't seem to answer. What exactly did the cords to to improve the reproduction?. And please keep in mind, you, like many other fan boys always claim "huge, immense, mind blowing, and in your words, a miracle. So I expect a clear obvious change anyone can hear.

And of course it's possible there is some deficiency or external technical influence at your site such as extreme RFI/EMI which the Shunytata cord is correcting for or masking. We can't discount that.

Quote:

My wife was told numerous time by certified professionals in the medical (MD) field the swelling in her neck was nothing to be worried about and kept sending her back. I said they are full of **** and insisted she get a biopsy. Turns out to be thyroid cancer. Oh well.... My grandmother and brother in law both died of non diagnosed cancer. Kept sending her to the gym - turns out to be colon cnacer. The day I blindly accept the opinion of a certified MD as truth is the day I'll sell my Shunyata cables (at a profit of course).

Sorry to hear that. I should have also mentioned any industry has it's share of quacks, even quacks with outstanding credentials. But based on my limited knowledge of cancer research is still in it's infancy. There have been major discoveries but there is still much unknown. Electrical signal transmission at audio frequencies, which certainly includes 60hz line power, is well understood and has been for decades. Still I feel we are for the most part better off following the advice of certified professionals. You got burned so I understand.

And why do used Shunyata power cords increase in value? I have heard that from others too! Is it a burn in thing? I'm just curious.

Well I have asked you this before and you can't seem to answer. What exactly did the cords to to improve the reproduction?. And please keep in mind, you, like many other fan boys always claim "huge, immense, mind blowing, and in your words, a miracle. So I expect a clear obvious change anyone can hear.

Of course I can answer, but what is the point? You're not going to change your mind based on my subjective description of "better sound", no matter what prose I use.

Quote:

Originally Posted by Glimmie

And why do used Shunyata power cords increase in value? I have heard that from others too! Is it a burn in thing? I'm just curious.

They don't, but if you buy them at the right price you can get out at break-even or make a slight profit - worse case you lose shipping cost and/or a few hundred bucks every now and then. I just bought some speakercable (current model) with MSRP of $14,000 for $4,500. You will probably think I'm insane. I just give them a try and if they don't beat the incumbent I'll sell them for $5,000. For me this is part of the fun.